CNC machine tools are able to accurately machine and produce parts. Recently, 4/5-axis machining is increasingly used for complex shapes, such as dies, molds, turbine blades, marine propellers, aerospace parts, etc. The additional degrees of freedom of the tool movement that it provides compared to three-axis machining offers many possibilities and advantages such as increased stability, better accessibility, reasonable tool employment and less required part-setups. Furthermore, the implementation of dynamic adaptation/optimization of the orientation of a milling cutter can also provide lower scallop height, larger possible step-over distance/value (“step-over”), and better surface quality.
In some instances, it may be desirable to maximize the step-over distance of a milling cutter in order to reduce machining time and thereby maximize productivity. It may also be desirable to minimize surface roughness of a machined product. These factors may be at odds with each other. Using conventional techniques, high step-over distances (providing high productivity) may yield unacceptably rough machined surfaces; while smooth machined surfaces may require low step-over distances (resulting in unacceptably low productivity). Thus, there is a trade-off between the step-over distance and the surface roughness, and it may be difficult to strike an optimal balance between these two apparently conflicting parameters.
While a variety of methods of controlling milling cutter orientation and step-over have been used, it is believed that no one prior to the inventors has made or used an invention as described herein.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the invention may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention; it being understood, however, that this invention is not limited to the precise arrangements shown.